Normally I'd say Boomkat.com, but they're out of stock at the minute. You could try eBay, but I reckon they'll most probably go for a packet.

Therapyrock - another one you'll like (probably more so than Proem) is Pale Glitter by Miwon. Same label as Schnauss (City Centre Offices) but a more quirky/pop feel to it, and in my book the best album of the year so far.